As the problems of indoor air pollution are getting severe, the public concerns on the conditions of their living and working environment as well as the health effects by the indoor air quality are increasing. At the same time, the guidelines and the rules to control and regulate the indoor air quality have been established in different countries. Hence, the demand for instruments and equipment on monitoring the air quality is increasing.
Conventionally, there are two major types of instruments for monitoring the indoor air quality. The first type of environmental monitoring instruments is employed mainly in the research laboratories. They are of considerably large scale. The second type belongs to the portable survey type instruments and they are much more compact in size.
The results obtained by the first type of environmental monitoring instrument are highly precise and accurate. Nevertheless, the prices of this type of instruments are significantly high. The operations of these instruments are complicated and only manageable by well trained and skillful technicians.
Generally speaking, each second type environmental monitoring instrument is equipped with a sensor for measuring a particular environmental parameter. The size of this type of instrument is therefore comparatively compact. Nevertheless, as different environmental parameters are inter-correlated, the level of a single parameter is usually affected by the levels of the other parameters. To obtain the level of a particular environmental parameter with a single sensor is usually not an all-round method. The precision obtained would be low. For examples, to measure the concentration of the volatile organic compounds solely by the photo-ionization detection method may give an inaccurate result as the detection method is easily affected by the temperature and relative humidity of the environment. In addition, different types of sensors with different working principles give different outcomes when they are employed for monitoring the same environmental parameter. For these reasons, there are usually difficulties to standardize the detection methods for the environmental parameters. In order to ensure an adequate and a moderately accurate result can be obtained for a single parameter, several instruments are usually brought to site during measurement. The results obtained are then evaluated together during analysis. The measurement processes by multiple instruments are rather inconvenience.
Nevertheless, for both types of environmental monitoring instruments being mentioned, only the raw data would be simply displayed and output. None of them would provide systematically analyzed information as described in the present invention.